Construction began in December with a vehicle processing hangar, launch pad, and roading upgrades now well under way.
Work on communications networks had begun, which would also improve internet speed for rural residents.
Rocket Lab spokeswoman Catherine Hammond said the company had chosen to employ local contractors where possible.
"We've enjoyed the opportunity to contribute to the local economy and have appreciated the support of contractors who know the area and landscape well."
Community members said the new site could open a world of possibility for Wairoa.
Wairoa mayor Craig Little said it was a bit of excitement for the town, and that "it'll be huge".
"At this stage its just another business come to town," he said, "but one business attracts more businesses."
Mr Little said the site would also be great for tourism: "Everyone knows where Cape Canaveral is in the United States. This will be the only one on this side of the world, it'll be huge for tourism."
Wairoa councillor Mike Bird said he could imagine people taking trips to the site to watch the satellites take off.
"When people start visiting they might want to come back and see the rest of our district."
He said the ongoing construction would mean work for a lot of people. "It's a win-win situation for Wairoa as far as I can see."
Alex Powdrell, facilitator of business action group Upstream Wairoa, said the launch site was definitely going to have a positive flow-on effect for the town.
The Onenui station site was blessed on November 28 and a lease agreement was signed between Rocket Lab and the landowners - Tawapata South Maori Incorporation. The Wairoa District Council lobbied to get the launch site.